Maintaining genetic diversity is important to make sure all kiwi taxa survive.
The aim of genetics research
Research into kiwi genetics aims to make sure managed kiwi populations maintain good levels of genetic diversity. For example, by carefully selecting which birds to move around during translocations and as part of Operation Nest Egg projects.
Genetic bottlenecks may have naturally occurred in the past, reducing the genetic diversity within a population and increasing its probability of extinction. Researchers think this is why kiwi were not historically found on islands smaller than Little Barrier Island/Hauturu (3000 hectares), in the Hauraki Gulf.
Little spotted kiwi
One research project is looking at the genetic diversity of little spotted kiwi using feather and blood samples collected over the years.
Because most little spotted kiwi live on Kapiti Island (about 1200), they have been the major source for translocations to create new populations elsewhere—about 200 birds so far. However, the Kapiti population was founded by only a handful of birds in the early 1900s, which means it has low genetic variation and/or a specific concentration of genes.
It may be that little spotted kiwi on Long Island, in the Marlborough Sounds, have different genetics. Two birds from a different lineage to the Kapiti birds were transferred there from D’Urville Island in the 1980s, and their genes may have mixed with Kapiti birds also transferred to Long Island.
The Kiwi Trust’s predecessor, BNZ Save the Kiwi Trust, helped fund initial research led by Victoria University to measure genetic differences within and between these little spotted kiwi populations. The information from this ongoing research should allow the Department of Conservation to manage genetic diversity by transferring particular birds between the populations.
Genetic research has lead to some exciting discoveries. In 1995, the tokoeka was found to be a separate species from brown kiwi, and in 2003, rowi was also recognised as a separate species from brown kiwi.
Further new developments are expected in the near future, particularly with new forms being described for brown kiwi and tokoeka.